On Wed, Jul 12, 2017 at 02:43:45PM +0200, Alexander Graf wrote:
> The current VNC default keyboard delay is 1ms. With that we're constantly
> typing faster than the guest receives keyboard events from an XHCI attached
> USB HID device.
>
> The default keyboard delay time in the input layer however is 10ms. I don't
> know
> how that number came to be, but empirical tests on some OpenQA driven ARM
> systems show that 10ms really is a reasonable default number for the delay.
>
> This patch moves the VNC delay also to 10ms. That way our default is much
> safer (good!) and also consistent with the input layer default (also good!).
And that still allows 100 keys to be sent in 1 second. If people are needing
to send more than this, they should be using a paravirt channel like the
SPICE agent which support high volume text cut + paste to the guest OS.
>
> Signed-off-by: Alexander Graf <ag...@suse.de>
Reviewed-by: Daniel P. Berrange <berra...@redhat.com>
> ---
> qemu-options.hx | 2 +-
> ui/vnc.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 76b1c67..6909285 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1753,7 +1753,7 @@ spec but is traditional QEMU behavior.
> @item key-delay-ms
>
> Set keyboard delay, for key down and key up events, in milliseconds.
> -Default is 1. Keyboards are low-bandwidth devices, so this slowdown
> +Default is 10. Keyboards are low-bandwidth devices, so this slowdown
> can help the device and guest to keep up and not lose events in case
> events are arriving in bulk. Possible causes for the latter are flaky
> network connections, or scripts for automated testing.
> diff --git a/ui/vnc.c b/ui/vnc.c
> index 26136f5..eb91559 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -3808,7 +3808,7 @@ void vnc_display_open(const char *id, Error **errp)
> }
>
> lock_key_sync = qemu_opt_get_bool(opts, "lock-key-sync", true);
> - key_delay_ms = qemu_opt_get_number(opts, "key-delay-ms", 1);
> + key_delay_ms = qemu_opt_get_number(opts, "key-delay-ms", 10);
> sasl = qemu_opt_get_bool(opts, "sasl", false);
> #ifndef CONFIG_VNC_SASL
> if (sasl) {
> --
> 1.8.5.6
>
>
Regards,
Daniel
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